Adjustable wrist-pin



(NoModeL) L. THOMAS.

WITNESSES: INVENTOR:

%Jm( '& BY J/(AMMN l TORNES.

NJHEBS. PHOTO-UTHOGRAPHER. WASHINGTON D C UNITED STATES PATENT OFFICE.

LAFAYETTE THOMAS, OF MARSHALL, MISSOURI.

ADJUSTABLE WRIST-PIN.

SPECIFICATION forming part of Letters Patent No. 234,090, dated November 2, 1880. Application filed September 14, 1880. (No model.)

To all whom it may concern.-

Be it known that I, LAFAYETTE THoMAs, of Marshall, in the county of Saline and State of Missouri, have invented a new and Improved Adjustable VVrist-Pin, of which the following is a specification.

The object of my invention is to provide a new and improved adjustable wrist-pin, which is simple in construction and convenient and effective in use, and prevents the noise and irregular motion.

The invention consists in a wrist-pin formed of a cylinder attached to the pitman, said cylinder fitting into the cap-shaped head of a pin that passes longitudinally through the cylinder, the pin being held in the desired position by a screw-nut provided with teeth in which a sliding spring-catch takes in order to prevent the nut from rotating.

In the accompanying drawings, Figure l is a longitudinal sectional elevation through the end of the pitman and through the adjustable wrist-pin. Fig. 2 is a plan view of the end of the pitmanrod.

A short tube, A, which is squared on the inner sides, is attached to and passes through the lower end of the pitman-rod B in such a manner that it projects from the lower side of the same.

A squared pin, 0, fitted exactly in the tube A, and passing through the same, is provided with a cap-shaped head, D, of sufficient size to receive the outer end of the tube A, and containin g a spiral spring, E. The forward end, F, of the pin 0 is rounded and provided with a screw-thread, in which a threaded square or polygonal nut, Gr, provided with an integral cog-wheel washer-plate, H, takes, the washerplate resting upon the upper surface of the pitma-n-rod, as shown.

A sliding latch, J, pressed against the eogged washer-plate H by a spiral spring, M, and provided with a stud, K, at the rear end, is contained in a casing, L, on the top of the pitman-rod.

The operation is as follows, if applied to a mowing-machine: The sickles or cutters of a mowing-machine are held between the pitmanrod B and the cap D, the cylinder A forming the pintle or wrist-pin of the same. It is necessary that the distance from the surface of the pitman-rod to the edge of the cap D shall not be greater than the thickness of the link,

sickle, or knife at the aperture for the pintle, and it is therefore desirable to be able to regulate the length of the pintle according to the thickness of the knife.

By turning the nut G from left to right the pin 0 is drawn in the direction of the arrow at. The end of the tube A passes into the cap D and compresses the spring E-that is, the Wrist-pin is shortened. By turning the nut in the opposite direction the wrist-pin is lengthened, for the spring E has the tendency to separate the cap D and the tube A; but to prevent an accidental turning or loosening of the nut G or of the pin 0, the latter is squared, and the nut is provided with the integral cogwheel washer H, which is locked by the sliding spring-catch J. If the wrist-pin is to be adjusted, the catch J must first be drawn back, so as to be disengaged from the cog-wheel washer H, and permit a rotation of the same and of the nut Gr attached thereto.

1 do not limit myself to the use of my wristpin in mowing-machines only, but may use it in any kind of machine.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

The tube A, squared on the inside and provided with squared pin (J, cup-shaped head D, spiral spring E, end screw, F, nut G, and cogged washer-plate H, in combination with a pitman-rod having a spring-latch, substantially as shown and described.

LAFAYETTE THOMAS.

\Vitnesses:

L. P. DOUGLASS, H. O. MILLER. 

